Electrical properties of epoxy-glue/(Bi12MnO20–BiMn2O5) composite:

Electrical properties of composite consisted of epoxy-glue and powdered bismuth manganite Bi12MnO20–BiMn2O5 ceramics were studied. Samples contained 66 wt% of bismuth manganite. Secondary electron images and backscattered electron images were collected for the epoxy-glue and the epoxy-glue/bismuth manganite samples. Microanalysis shown that majority of bismuth manganite powder was homogenously distributed in epoxy-glue matrix. Lack of changes in crystallographic structure, in 300–450 K range, was deduced from the X-ray diffraction patterns. The electric impedance was measured at radio-frequencies. It was analysed using electric permittivity ɛ*(T, f ) and modulus M″(T, f ) representation. Epoxy-glue/bismuth manganite composite exhibited, at room temperature, conductivity, σ(f ) = 10−5 to 10−7 S m−1, permittivity, ɛ′≈10, losses, tan δ = 0.2–0.8 and dispersion markedly lower than bismuth manganite ceramics. Electric relaxation was induced in epoxy-glue/bismuth manganite composite samples. The Vogel–Fulcher–T...